Ultrasonic interrupter



July 5, 1966 R. D. BUELL, JR., ETAL 3,259,103

ULTRASONIC INTERRUPTER Filed 001;. 21, 1963 2 h h e l I N VENTORS Pay Q Ede/J c/n 8 en 5. F/e/mson July 5, 1966 R. D. BUELL, JR., ETAL 3,259,103

ULTRASONIC INTERRUPTER Filed Oct. 21, 1963 2 Sheets-Sheet 2 72 lNVENTOR-ES Gay 0. Ede c/n BYBI7 B-P/Q/JM A TORNEYS United States Patent 3,259,103 ULTRASONIC INTERRUPTER Roy D. Buell, Jr., Hinsdale, and Ben B. Peterson, Worth, 111., assignors to Buell Manufacturing Company, Lyons, Ill., a corporation of Illinois Filed Oct. 21, 1963, Ser. No. 317,675 3 Claims. (Cl. 116-137) such frequencies have been effectively used to control rodents in granaries. These ultrasonic generating transducers generally produce a constant or steady note.

It has been discovered that the constant or steady note is not as eifective in rodent control as .a succession of series of sharp staccato notes or varying notes or sounds of changing frequencies. Therefore, the present invention is drawn to an improved ultrasonic transducer that will produce an interrupted ultrasonic note and to an improved interrupter for a compressor that delivers pressurized fluid to an ultrasonic transducer.

Therefore, it is an object of the present invention to provide an improved interrupted ultrasonic transducer.

It is another object of the present invention to provide an ultrasonic transducer that will generate ultrasonic interrupted sound waves.

It is still another object of the present invention to provide an ultrasonic transducer having a resonator with a resonator cavity having a sharp cavity edge and a nozzle spaced to direct pressurized fluid before the resonator cavity edge and across the entire mouth of the resonator cavity and spin ball means adapted to periodically restrict the flow of pressurized fluid into the nozzle to thereby generate an interrupted ultrasonic sound wave.

It is still a further object of the present invention to provide an ultrasonic transducer for generating interrupted ultrasonic sound waves having a housing with an inlet and an outlet being formed by a pressurized fluid nozzle and said housing defining a generally annular chamber with at least two spin balls retained in said chamber and spaced from each other to periodically restrict flow through the nozzle outlet when pressurized fluid is delivered to the housing. I

It is still further another object of the present invention to provide an improved interrupter adapted to feed interrupted pressurized fluid to an ultrasonic transducer.

It is another object of the present invention to provide a spin ball pressurized fluid interrupter having a housing defining an annular chamber containing at least one spin ball therein and the outlet for said chamber being an axially extended pipe with the outlet opening for the pipe being spaced a predetermined distance from one end wall and at least one spin ball rotating around the axial outlet conduit to periodically restrict the pressurized fluid inlet opening for the chamber.

Other features and objects of the present invention will become apparent to those skilled in the art after a careful consideration of the following detailed description when considered in conjunction with the accompanying drawings wherein like reference numerals and characters refer to like and corresponding parts throughout the several views.

On the drawings:

FIGURE 1 is a side elevational view of a double bell amplifier equipped with an ultrasonic transducer constructed in accordance to the principles of the present invention;

FIGURE 2 is an enlarged transverse cross-sectional view with parts in elevation of the ultrasonic transducer of the present invention taken along lines II-II of FIGURE 1;

FIGURE 3 is a partial longitudinal cross-sectional view of the ultrasonic transducer illustrated in FIGURE 2;

FIGURE 4 is a longitudinal cross-sectional view with parts in elevation of an ultrasonic transducer interrupter constructed in accordance to the principles of the present invention;

FIGURE 5 is a transverse cross-sectional view with 7 parts in elevation, of the interrupter illustrated in FIG- URE 4;

FIGURE 6 is a transverse cross-sectional view, with parts in elevation, illustrating another embodiment of an interrupter constructedin accordance to the principles of the present invention;

FIGURE 7 is a transverse cross-sectional view with parts in elevation, illustrating another embodiment of an interrupter constructed in accordance to the principles of the present invention;

FIGURE 8 is a transverse cross-sectional view with parts in elevation, illustrating a further embodiment of an interrupter constructed in accordance to the principles of the present invention;

FIGURE 9 is a transverse cross-sectional view, with parts in elevation, illustrating still another embodiment of an interrupter constructed in accordance to the principles of the present invention;

FIGURE 10 is a partial transverse elevational view illuistrating another embodiment of the present invention; an

FIGURE 11 is a longitudinal cross-sectional view with parts in elevation, illustrating another embodiment of an interrupter constructed in accordance with the principles of the present invention.

As shown on the drawings:

An interrupted ultrasonic transducer constructed in accordance to the principles of the present invention is part of an assembly which is connected to the interior of a bell shaped amplifier. The interrupted transducer has a housing which is aflixe'd to the amplifier interior. The transducer housing has a tangential or nonradial inlet nozzle leading into an annular pressure chamber and a radially extending nozzle outlet leading from the pressure chamber into a venturi shaped passage. A resonator having a resonator cavity is spaced a predetermined distance from the outlet nozzle so that pressurized fluid flowing through the outlet nozzle is directed before the mouth of the resonator cavity edge and across the entire month of the resonator cavity. At least two spin balls are rotatably mounted in said annular housing to rotate around the venturi passage and to periodically overlay the nozzle outlet opening in the pressure chamber to provide interrupted sound waves.

Another embodiment of the present invention further provides an interrupter having an outlet conduit to be connected to the inlet conduit of an ultrasonic transducer. The interrupter has a generally cylindrical housing with two end walls. One end wall has an outlet conduit axially extending therethrough with an end thereof spaced a short distance from the inner surface of the other end wall. The arcuate side wall is provided with an inlet opening to admit pressurized fiuid into the housing in a is mounted in the housing and adapted to rotate around the axis thereof in contact withthe cylindrical inner surface so as to periodically restrict the inlet opening.

Referring to FIGURES 13, there is illustrated an interrupted ultrasonic transducer 11 being connected to the interior of a tubular double bell mouthed housing 12. The double bell housing is used to amplify and direct the interrupted ultrasonic sound waves produced by the transducer 11. The double be-ll housing is composed of plastic, metal or the like.

It is of course understood that the interrupted ultrasonic transducer 11 may be connected to any type of amplifying and directing means and the amplifying and directing means may even be completely eliminated without effecting the generation of interrupted ultrasonic sound waves.

Referring to FIGURES 2 and 3, the interrupted ultrasonic transducer has a cylindrical housing 13 with a concentric cylindrical inner wall 14 and an outer cylindrical wall 16. The inner wall forms an axially extending converging-diverging or venturi passageway 17, which has its open ends facing the mouths of the double bell amplifier 12, and the outer wall 16 is suitably connected to the inner wall 14 by radially extending axially spaced end walls 18 and 19 to form an annular pressure chamber 21 surrounding the passageway 17.

A resonator plug 22 is attached to the inner wall 14. The resonator 22 has a frusto-conical end 23 extending radially into the passageway 17 normal to the axial center line thereof. The frusto-conical end forms a cylindrical resonator cavity 24 that has a mouth which opens into the passageway 17 and preferably extends normal to the axis thereof. The resonator end wall is finished to have a sharp resonator cavity mouth edge inwardly spaced from an end wall sharp outer edge.

A transducer nozzle 26 is connected to the inner wall 14 and has a frusto-conical exit end portion 27 extending radially into the passageway 17 and normal to the axis thereof. The transducer nozzle forms a cylindrical passageway 28 therethrough with an open outlet end 29 that would deliver pressurized fluid in a stream that was substantially normal to the axis of the passageway 17, and an open inlet end 31 communicating with the interior of the pressure chamber 21. It is of course understood, that the surface of the inlet 31 does not have to be continuous with the outer surface 32 of the inner wall 14, but may be inwardly spaced from the inner wall outer surface 32. It only being necessary that the transducer nozzle inlet 31 communicate with the interior of the pressure chamber 21.

The frusto-conical end portions of the transducer nozzle and resonator are finished and shaped so.that they may be positioned in close proximity to each other. It is of course understood that the nozzle and resonator end portions may have any shape desired. However, in this type of transducer, a sharp cavity edge finishing is essential to the effective operation of the resonator 22. The transducer nozzle is preferably connected to the housing so that the axial center line of fluid ejecting through the nozzle outlet intersects the axial center line of the resonator cavity at an angle of approximately 120.

At least two balls 33 are located in the pressure chamber 21. The diameter of all the balls 33 are the same and are held in the central portion of the housing by a pair of inwardly extending circular race walls 35. The race walls are spaced such that the balls will pass over the nozzle inlet 31 and remain in their relative position and also have sufficient room for free spinning. The number of balls control the amount of periodic interruptions for the transducer. The interruptions are also controlled by the weight and the surface friction of the balls. The halls must be light enough to spin in the 1 to p.s.i. air stream used by the present transducer. The balls may be of different weights and sizes if it is desired and can be composed of metal, plastic, glass or even wood. How-' ever, too great a size difference between the balls will the pressure chamber.

cause them to jam. Also, it is desirable in this type of interrupted transducer to use more than one spin ball in One ball tends to come to rest and close over the nozzle inlet and thus put the transducer out of operation. This problem does not occur with the use of more than one ball.

A supply or inlet conduit 34 is connected to the outer walls 16 and passes through the amplifier 12. The supply conduit forms a passage 36 therethrough and has a tapered outlet 37 communicating with the pressure chamber 21. The tapered supply outlet is preferably displaced less than from and faces the nozzle inlet 31 to direct pressurized fluid in a tangential or non-radial circumferential or helical path into the pressure chamber 21. The supply conduit is connected to a suitable pressurized fluid supply means, such as an air compressor 0, to supply pressurized fluid to the conduit at a pressure of approximately l15 p.s.i. and preferably between 3 to 9 p.s.i.

In operation, pressurized air is delivered to the inlet conduit 34. The air pressurizes the chamber 21 and undergoes a pressure drop. The air within the chamber sets up an air stream to spin the balls 33 and rotate the balls around the inner wall 14. Meanwhile air is exited from the pressure chamber through the transducer nozzle 26 and towards the transducer resonator 22, to provide an ultrasonic sound wave. However, as the balls 33 rotate and spin about the inner wall 14, they approach and pass over the transducer nozzle passageway inlet end 31 to restrict the inlet opening at predetermined periodic intervals to produce interrupted or staccato ultrasonic sound waves. The balls themselves open smoothly about the wall 14 like ball hearings in a bearing assembly although they are relatively loose between the inner wall 14 and the outer wall 16.

Referring to FIGURES 4 and 5, there is illustrated an interrupter 41 constructed in accordance to the principles of the present invention. The interrupter 41 is adapted to be connected between an ultrasonic transducer and a source of pressurized fluid, such as air, to have the ultrasonic transducer produce interrupted ultrasonic sound waves.

The interrupter 41 has a cylindrical housing 42 forming a cylindrical pressure chamber 43 with an annular side wall 44, a front circular end wall 46, and a rear cir cular end wall 47. An outlet conduit 48 projecting through the center of the front wall 46 forms a flow passage 49 with an inlet or inner end 51 and an outlet end 52. The outlet conduit extends into the pressure chamber 43 approximately along the axial center line thereof and through the front wall 46 with the inlet end 51 being spaced from the inner surface of the rear wall 47 less than one-half of the distance between the front wall 46 and the rear wall 47.

A- cylindrical delivery inlet port 53 is formed preferably in the axial center of the annular wall 44. The port 53 is formed to direct the inlet air in a nonradial and preferably tangential direction into the pressure chamber 43 or inlet 53 has communicating therewith a conduit 54 to deliver pressurized fluid thereto from a suitable source (not shown).

A spin ball 56 is located within the pressure chamber 43 and is of a predetermined diameter and weight to spin and rotate around the conduit 48 along the inner periphery of the pressure chamber 43 when pressurized air is supplied to the delivery conduit 54 at between 1 and 15 ps1.

As seen in the drawings, the diameter of the ball 56 is less than the distance between the conduit 48 and the side wall 44, and is also less than the distance between the inner end 51 of the conduit 48 and the rear wall 47 to preclude closing of the flow passage 49 by the ball 56.

In operation, pressurized fluid, such as air, is delivered to the conduit 54 and injected into the pressure chamber 43 through the delivery port 53. The injected air forms an air stream that spins the ball 56 and causes the ball to rotate around the conduit and along the inner surface of the wall 44. The pressure chamber is sized and the port 53 is sized and positioned such that the ball 56 will in predetermined periods pass thereover to periodically restrict the inlet port 53. The air within the pressure chamber is delivered to the supply conduit 48 through the supply conduit inlet 51 and from there to a suitable ultrasonic transducer (not shown). Therefore, the air delivered to the supply conduit 48 is not a steady pressure but a pressure that has been periodically momentarily interrupted. Thus, the ultrasonic transducer receiving air from supply conduit 48 will produce interrupted ultrasonic sound waves.

Referring to FIGURES 6 and 7 there are illustrated interrupters 61 and 61a constructed in the same manner as the interrupter 41. However, the interrupter 61 has two spin balls 62 and the interrupter 61a three spin balls 63. The spin balls in each interrupter have substantially the same diameters but not necessarily the same predetermined weights. The spin balls 62 and 63 are spaced equidistant from each other and are of such a diameter that they are in approximate simultaneous contact with the inner periphery of the wall 44 and the outer surface of the supply conduit 48. The balls 62 and 63 are sized such that they remain in position but are yet free to spin and rotate along the inner periphery of wall 44 to pcriodically restrict flow injected into the pressure chamber 43 through a cylindrical inlet port 64. The inlet port 64 is formed through the center of the wall 44 such that it has a bottom that is continuous with a tangent to the inner circumference of the wall 44.

A suitable conduit means (not shown) connected to the wall 44 will deliver pressurized fluid from a suitable source to the supply port 64.

Referring to FIGURES 8 and 9 there are illustrated two more interrupters 71 and 72 constructed in accordance to the principles of the present invention. The interrupters 71 and 72 are similar to the interrupter 61 except that the interrupter 71 has four spin balls 73, two pairs each of diiferent weights and alternately speed therein that are in approximate contact with each other as well as the conduit 48 and the inner periphery of the wall 44 and are still free enough to spin and rotate about the conduit 48, and the interrupter 72 has five spin balls 74 therein that are in approximate contact with each other and the inner periphery of the wall 44 and are free enough to spin and rotate about the conduit 48.

It is of course understood that the number of spin balls and their relationship to one another in the pressure chamber 43 applies also to the transducer pressure chamber 21 (FIGURE 2).

The number of balls controls the frequency of tthe interruptions. Also,interruption is controlled by tthe weight and the surface friction of the balls.

Referring to FIGURE 10, there is shown another embodiment of the interrupters 41, 61, 61a, 71 and 72. This embodiment has a flexible diaphragm 76 secured around its periphery in a cylindrical holder 77 on the rear wall 47 of the housing. 42. The diaphragm overlies and normally closes the supply conduit inlet 51. Air introduced into the chamber 43 will pressurize the pressure chamber 43 to a predetermined desired level and the diaphragm will deflect or move to allow air to pass into the inlet 51 through the supply conduit to the transducer. When one of the located spin balls in the pressure chamber interrupts the inlet air stream, the chamber pressure is momentarily reduced, and the diaphragm closes the supply conduit inlet 51 like a valve. Thus a periodic interruption of the pressurized air stream passing through the conduit 48 to the ultrasonic transducer provides interrupted ultrasonic sound waves. The diaphragm 76 can be a thin flexible metal or plastic disk.

Referring to FIGURE 11, there is illustrated another interrupter 81 constructed in accordance with the principles of the present invention. The interrupter 81 is similar to the interrupters 41, 61, 61a, 71 and 72.

It has a cylindrical housing 82 forming a cylindrical pressure chamber 83 with an annular side wall 84, a front 5 circular end wall 86, and a rear circular end wall 87. An outlet conduit 88 is connected to the front circular wall 86 and terminates flush with the inner surface of the circular wall 86. The outlet 88 has a flow passage 89 communicating with the interior of the pressure chamber 83.

An inlet (not shown) is formed in the annular wall 84 to direct air in a nonradial and preferably tangential direction into the pressure chamber 83. At least two spin balls 91 are located within the pressure chamber 83. The spin balls 91 have a predetermined diameter and weight to spin and rotate, while in contact with one another, along the inner periphery of the pressure chamber 43 when pressurized air is supplied to the inlet at between 1 and p.s.i. The injected air forms an air stream that spins the balls 91 and causes the balls to rotate along the inner surface of the wall 84. The pressure chamber is sized and the port in the inlet is sized and positioned such that the balls 91 will, in predetermined periods, pass thereover to periodically restrict the inlet. Therefore, the air delivered from the pressure chamber to the outlet 88 is not steady but is a periodically momentarily interrupted pressure supply. The outlet conduit is suitably connected to an ultrasonic transducer and will therefore cause the ultrasonic transducer to produce interrupted ultrasonic sound waves.

Therefore, it is seen where we provide an improved means for producing interrupted ultrasonic sound waves to act as an irritant for small cranium creatures.

It will be understood that the above embodiments of our invention have been for illustrative purposes only and that other embodiments may be effected without departing from the spirit and scope of the invention as set forth in the hereunto appended claims.

We claim as our invention:

1. A spin ball pressure interrupter for use in an ultrasonic sound system having a source of pressurized fluid, a fluid operated resonator adapted to produce ultrasonic sound waves at a frequency which varies with variations in pressure of the fluid, and means communicating the source of fluid with the resonator, said interrupter being arranged for interposition in the communicating means for varying the pressure of the fluid to the resonator, said interrupter comprising a housing having an annular side wall and'a pair of end walls and forming a cylindrically shaped chamber within said walls,

means forming a fluid inlet in said side wall for receiving pressurized fluid from said source and for directing the fluid in a non-radial direction into said chamber,

a tubular conduit having a circular cross-section along its entire length and having an outside diameter which is substantially less than the inside diameter of said chamber and extending from one of said end Walls into said chamber and having an open inner end terminating in spaced relation to the other of said end walls to provide a non-closeable outlet for the fluid in the chamber, and

at least one ball carried within the chamber and having a diameter which is less than the distance between said conduit and said side wall so as to be moved around said conduit and over said fluid inlet to interrupt the flow of fluid through said inlet and to vary the fluid pressure at said outlet, the distance between the open inner end of said conduit and said other end wall being less than the diameter of said ball.

2. A spin ball pressure interrupter for use in an ultrasonic sound system having a source of pressurized fluid, a fluid operated resonator adapted to produce ultrasonic 5 sound waves at a frequency which varies with variations in pressure of the fluid, and means communicating the source of fluid with the resonator, said interrupter being arranged for interposition in the communicating means for varying the pressure of the fluid to the resonator, said interrupter comprising a housing having an annular side wall and a pair of end walls and forming a cylindrically shaped chamber within the said walls,

means forming a fluid inlet in said side wall for receiving pressurized fluid from said source and for directing the fluid in a non-radial direction into said chamber,

a tubular conduit having a circular cross-section along its entire length and having an outside diameter which is substantially less than the inside diameter of said chamber and extending from one of said' end walls into said chamber and having an open inner end terminating in spaced relation to the other of said end walls to provide a non-closeable outlet for the fluid in the chamber, and

a plurality of balls carried within said chamber each having a diameter which is less than the distance between said conduit and said side wall so as to be moved around said conduit and over said fluid inlet to interrupt the flow of fluid through said inlet and to vary the fluid pressure at said outlet,

the distance between said open inner end of said conduit and said other end wall being less than the diameter of each of said balls. 3. The spin ball pressure interrupter as defined in claim 2 wherein the diameters of all of said balls are the same.

References Cited by the Examiner UNITED STATES PATENTS 867,430 10/ 1907 Simmons 23269 2,304,839 12/1942 Matheson 137-624.14 2,315,570 4/1943 White 137624.14 2,519,619 8/1950 Yellott et a1. 116-137 2,793,009 5/1957 Peterson 2591 2,800,100 7/1957 Boucher 116-137 3,157,154 11/1964 Moe et a1 116-137 LOUIS J. CAPOZI, Primary Examiner. 

1. A SPIN BALL PRESSURE INTERRUPTER FOR USE IN AN ULTRASONIC SOUND SYSTEM HAVING A SOURCE OF PRESSURIZED FLUID, A FLUID OPERATED RESONATOR ADAPTED TO PRODUCE ULTRASONIC SOUND WAVES AT A FREQUENCY WHICH VARIES WITH VARIATIONS IN PRESSURE OF THE FLUID, AND MEANS COMMUNICATING THE SOURCE OF FLUID WITH THE RESONATOR, SAID INTERRUPTER BEING ARRANGED FOR INTERPOSITION IN THE COMMUNICATING MEANS FOR VARYING THE PRESSURE OF THE FLUID TO THE RESONATOR, SAID INTERRUPTER COMPRISING A HOUSING HAVING AN ANNULAR SIDE WALL AND A PAIR OF END WALLS AND FORMING A CYLINDRICALLY SHAPED CHAMBER WITHIN SAID WALLS, MEANS FORMING A FLUID INLET IN SAID SIDE WALL FOR RECEIVING PRESSURIZED FLUID FROM SAID SOURCE AND FOR DIRECTING THE FLUID IN A NON-RADIAL DIRECTION INTO SAID CHAMBER, A TUBULAR CONDUIT HAVING A CIRCULAR CROSS-SECTION ALONG ITS ENTIRE LENGTH AND HAVING AN OUTSIDE DIAMETER WHICH IS SUBSTANTIALLY LESS THAN THE INSIDE DIAMETER OF SAID CHAMBER AND EXTENDING FROM ONE OF SAID END WALLS INTO SAID CHAMBER AND HAVING AN OPEN INNER END TERMINATING IN SPACED RELATION TO THE OTHER ORF SAID END WALLS TO PROVIDE A NON-CLOSEABLE OUTLET FOR THE FLUID IN THE CHAMBER, AND AT LEAST ONE BALL CARRIED WITHIN THE CHAMBER AND HAVING A DIAMETER WHICH IS LESS THAN THE DISTANCE BETWEEN SAID CONDUIT AND SAID SIDE WALL SO AS TO BE MOVED AROUND SAID CONDUIT AND OVER SAID FLUID INLET TO INTERRUPT THE FLOW OF FLUID THROUGH SAID INLET AND TO VARY THE FLUID PRESSURE AT SAID OUTLET, THE DISTANCE BETWEEN THE OPEN INNER END OF SAID CONDUIT AND SAID OTHER END WALL BEING LESS THAN THE DIAMETER OF SAID BALL. 